respiratory system

• Aerobic Respiration


  Aerobic repitation exercise can be maintained for long periods of time, includes activities like walking, jogging, cycling & swimming, the intensity of exercise is moderate & duration long
• Aerobic Respiration


  1. glucose

  2. oxygen

  3. energy

  4. Carbon dioxide

  5. water
• Aerobic Respiration


  • marathon runner
  • long-distance swimming
• Anaerobic Respiration


  when you exercise at a high intensity, the respiratory system cannot Supply enough oxygen to the muscles, with no oxygen available, glucose is still used but produces energy & lactic acid (this causes fatigue), it includes activities like sprinting, weightlifting, jumping, the intensity of exercise is high & duration short
• Anaerobic Respiration


  1. glucose

  2. energy

  3. lactic acid
• Anaerobic Respiration


  • 100m sprint
• Inspiration


  1. External muscles contract

  2. Internal intercostal muscles relax

  3. Ribs move upwards & outwards

  4. Chest expands

  5. Diaphragm contracts & flattens

  6. Lungs increase in size

  7. Pressure inside lungs falls

  8. Air sucked in through nose & mouth
• Expiration


  1. External intercostal muscles relax

  2. Internal intercostal muscles contract

  3. Ribs move downwards & inwards

  4. Chest gets smaller

  5. Diaphragm relaxes & domes

  6. Lungs decrease in size

  7. Pressure inside lungs increases

  8. Air forced out through nose & mouth
• Pathway of air


  • Air enters mouth/nose
  • Travels down pharynx, epiglottis, larynx
  • Continues down trachea to bronchi then bronchioli
  • Finally reaches alveoli where gaseous exchange occurs
• Gaseous exchange


  1. Air enters alveoli high in O₂ and low in CO₂

  2. Alveoli have good blood supply from capillaries

  3. O₂ diffuses into bloodstream, CO₂ diffuses out

  4. Capillaries are one cell thick for easy diffusion

  5. Slow down red blood cells
• Tidal volume


  The volume of air that is inspired or expired per breath
• Breathing rate


  The number of breaths per minute
• Minute ventilation


  The volume of air that is inspired or expired in 1 minute